1. Technical Field
The present invention relates a semiconductor device, a method of manufacturing, a circuit substrate and an electronic apparatus. In particular, the invention relates to a semiconductor device and a method of manufacturing there same having highly reliable connections, a circuit substrate and an electronic apparatus in which the semiconductor device is installed.
2. Related Art
To mount a semiconductor device with high density, it is preferable to mount a semiconductor chip as it is without packaging such as bare chip mounting. In bare chip mounting, however, insufficient protection is provided for a semiconductor chip and it is hard to handle. Hence, a semiconductor device using a chip size package (CSP) is proposed and a wafer level CSP in which a diced wafer becomes a semiconductor device without modification has been recently developed. In this wafer level CSP, resin layers and wirings are formed on a surface of a silicon wafer in which tiny transistors are fabricated. This silicon wafer is cut into individual semiconductor devices so as to yield a semiconductor device.
In the conventional method of manufacturing a semiconductor device using a wafer level CSP, when a resin layer is formed on a surface of a silicon wafer, the resin layer is not formed in a portion which is diced (i.e., cut) so as to avoid the loosening of a resin layer and the cracking of an end area of a semiconductor device (see International Patent Publication No. 01-071805 pamphlet (FIG. 1 and FIG. 14)).
In the conventional method of manufacturing a semiconductor device using a wafer level CSP, however, a resin layer and an external terminal are formed close to the center of a semiconductor element and the external terminal is connected to wiring extending from an electrode formed in a circumferential part of the semiconductor device. In this case, there is a problem in that a portion of the wiring connected to the external terminal is easily disconnected by stress and the like applied to the semiconductor device if the wiring extends in the center direction of a semiconductor element from the electrode and is directly connected to the external terminal. In particular, in the case of wafer level CSP, a portion for forming the external terminal of a wiring (called a land) is large and the root of this land may become disconnected.
Further, in the conventional method of manufacturing a semiconductor device using a wafer level CSP, there is another problem in that the root of the land formed in the circumferential part of a semiconductor device is easily disconnected due to the large stress at the areas remote from the center of the semiconductor device if the chip size is large. In the conventional method of manufacturing a semiconductor device, there is a further problem in that a wiring extends from the surface of a semiconductor device in which electrodes are formed to the surface of a resin layer so as to form a step in the wiring which makes it difficult to provide fine wiring.
The present invention aims to provide a semiconductor device, which can correspond to a large size chip and be provided with many external terminals with fine wirings with highly reliable connections. Further, the invention aims to provide a method of manufacturing the semiconductor device, and a circuit substrate and an electronic apparatus in which the semiconductor device with highly reliable connections is installed.